Self-tightening clamps made from spring wire or spring steel band material are known as such in the prior art. Such types of clamps are commercially available, for example, as "Mubea" clamps. As known, such self-tightening clamps produce the clamping force by the inherent elasticity causing the clamps to assume a reduced diametric dimension. To install these types of clamps, they have to be opened against the inherent spring force present in the band material. To that end, the prior art self-tightening clamps are provided with outwardly projecting distal ends or tabs for engagement by a suitable tool. However, such tool-engaging tabs which project radially outwardly a substantial distance, represent an ever-present source of injury, for example, in assembly work within the area of the engine compartment or at other, not easily accessible places, such as the fuel tank, fuel lines, fuel vent lines, CV joints, etc., not to mention the fact that in many applications, such as in the automotive industry, projecting parts in such clamps are undesirable in many cases for lack of adequate space.
Self-tightening clamps, which can be held in the open position for delivery to the customer are also known in the prior art. For example, European patent application 0 303 505 describes several embodiments in which either a separate holder is placed over the radially outwardly distal ends of projecting tabs (FIGS. 19 and 20 of the EP 0 303 505 A1) or a radially outwardly directed tab, formed at one distal end of the clamping band has to be displaced in front of a support piece to temporarily lock the clamp in the open or expanded position.
The German Patent DE 36 33 486 C1 as also the German patent DE 38 32 875 C1 describe other constructions of self-tightening clamps in which radially outwardly directed tabs can be temporarily locked in the open clamp position.
The prior art self-tightening clamps of the type described hereinabove all entail certain drawbacks. They all involve tab members extending relatively far radially outwardly, which is undesirable if not unacceptable for injury and/or space reasons pointed out hereinabove. Additionally, many of these prior art clamps require special tools to open and/or release the temporarily locked clamp after installation over the hose to be tigthened. This, in turn, jeopardizes their use in markets other than the OEM market, such as in the after-market. Furthermore, there exists always the danger that such prior art clamps are installed incorrectly, absent the use of the special tools, which may lead to product liability claims that involve substantial costs to establish the absence of liability of the manufacturer for the incorrectly mounted clamps. Additionally, these prior art clamps entail the disadvantage that they do not assure an internal clamping surface devoid of any steps or gaps which is important to minimize leakages within the area of gaps or steps.